Mineral oil composition and improving agent therefor



' the oil in certain respects.

Patented May 11, 1943 UNITED STATES PATENT OFFICE MINERAL OILCOMPOSITION AND IMPROV- ING AGENT THEREFOR Orland M. Reiii', Woodbury,N. 1., assignor to Socony-Vacuum Oil Company, Incorporated, New York, N.Y., a corporation of New York No Drawing. Application April 19, 1940,

Serial No. 330,532

16 Glaims.

This invention has to do in a general way with mineral oil compositionsand is more particularly related to mineral oil compositions of thelubricant type to which an agent has been added in a minor proportionfor the purpose of improving It is an object of this invention toprovide a novel class of mineral oil addition agents which will improveone or more important properties of a mineral oil fraction. It is afurther object to provide improved mineral oil compositions containingthese novel addition agents.

. In my copending application Serial No. 222,755,

filed August 3, 1938 (Patent 2,197,835), of which this application is acontinuation in part, I have described as mineral oil addition agents ageneral class of metalorganic compounds which are characterized by thepresence of a wax-substituted aryl nucleus, such addition agents beingof multifunctional properties in that they are effective to reduce thepour point, improve the viscosity index, and retard the deleteriouseffects of oxidation in the oil to which they are added.

. The present invention is predicated upon the discovery that the sulfurderivatives or, more specifically, the sulfides (monosulfides andpolysulfides) of metalorganic compounds of the type described in theaforesaid application are improved in certain respects over thecorresponding metalorganic compounds from which the sulfides may beconsidered as having been obtained. In addition to the sulfides orsulfur derivatives my invention also contemplates the correspondingderivatives of the related elements, selenium and tellurium.

More specifically, the present invention is concerned with metalorganiccondensation products of sulfur, selenium, or tellurium corresponding ingeneral to the alkyl-substituted aromatic-carboxylic acid saltsdisclosed in copending application Serial No. 300.010. filed October 18,1939 Patent 2,198.2'75L of which I am a coinventor. The addition agentsof the present invention are, like those of this last-mentionedapplication, characterized by the presence of an aromatic nucleus inwhich at least one nuclear hydrogen atom is substituted with anoil-solubilizing alkyl group and in which at least one other nuclearhydrogen atom is substituted with an organic preferably aliphatic orcycloaliphatic) carboxylic acid salt radical wherein the carboxylhydrogen is substituted with its equivalent weight of metal.

The addition agents of the present application are distinguished fromthose of application No. 300,010 in that at least two of the alkylatedaromatic-aliphatic acid salt radicals are interconnected by at least oneatom of an element selected from the group consisting of sulfur,

sulfur, for example, in the manner or manners to be hereinafterdescribed, I obtain what may be broadly termed a sulfide of analkyl-substituted aromatic-aliphatic carboxylic acid salt in which thecarboxyl hydrogen is substituted with its equivalent weight of metal.The term "aliphatic" as used herein to designate the aliphatic acid saltsubstituent is inclusive of straight and branched chain aliphatic groupsand cycloaliphatic groups, which may or may not carry othersubstituents.

The class of sulfides of alkylated aromaticaliphatic carboxylic acidsalts (or carboxylates) contemplated herein distinguishes over thecorresponding carboxylates of copending application No. 300,010 in thatthe sulfides have increased effectiveness in retarding the deleteriouseffects of oxidation in the oil. In the preferred class ofmultifunctional addition agents, I have found that the sulfides possessimproved properties for inhibiting against the formation of oxidationproducts in the oil over the corresponding carboxylates or salts ofcopending application No. 300,010. The improved inhibiting propertiesare particularly significant in retarding the development of acidity incertain types of oils and under certain conditions of use.

The property of oil-miscibility-that is, of remaining uniformlysuspended in the oil under normal conditions of handling and use-isimparted to the condensation products contemplated herein by the alkylsubstituent on the aryl nucleus. This substituent, therefore, should bederived from an aliphatic hydrocarbon oi sufliciently high molecularweight, or the aryl nucleus should be sufficiently substituted (oralkylated), to render the product oil-miscible. The degree ofsubstitution necessary to accomplish this will vary with the characterof the aromatic nucleus (monocyclic or polycyclic) and also with thecharacter of the organic group in the organic acid substituent. A longchain aliphatic group in the organic acid salt substituent. such as astearic acid group, for example, will require less substitution of thearyl nucleus than a short chain aliphatic acid group such as aceticacid. For obtaining the preferred product having multifunctionalproperties, the alkyl substituent, as aforesaid, should correspond to analiphatic hydrocarbon having at least twenty carbon atoms. A petroleumwax such as paraffin wax constitutes a preferred source for thesesocalled heavy alkyl substituents, and for that reason the preferredmultifunctional compounds may be hereinafter designated aswax-substituted." It is to be understood, however, that the term "wax asused in this regard is not restricted to substituent groups derived frompetroleum wax but is intended to include substituent groups derived fromany aliphatic hydrocarbon or mixture thereof or any predominantlyaliphatic material which is, in character or constituents, similar tothe constituents of petroleum wax.

The condensation products of alkyl-substituted aromatic-aliphaticcarboxylic acid salts of the type contemplated herein as oiladditionagents may be characterized by the general formula:

2. I coon-l COOM] I 11-11 --2l---'{R Yr .1 LY:

in which T represents a monocyclic or a polycyclic aromatic nucleus; 2represents sulfur, selenium, or tellurium; and n represents a wholenumber from one to four. The group Z.COOM represents what may be broadlytermed an organic carboxylic acid salt group in which Z is preferably analiphatic or cycloaliphatic hydrocarbon group attached to T and COOMrepresents a carboxyl group attached to Z, the carboxyl hydrogen thereofbeing substituted with its equivalent weight of a metal M. It representsat least one oil-solubilizing alkyl group which for the preferredmultifunctional compounds is at least one alkyl group containing atleast twenty carbon atoms, hereinabove identified as a wax" group. Inaddition to the oil-solubilizlng alkyl group R, the characterizing arylnucleus T may contain hydrogen as added hydrogen obtained byhydrogenation or it may contain residual hydrogen a part or all of whichmay, in turn, be substituted with a substituent or substituents having apositive or negative or neutral oil-solubilizing effect. Such hydrogenor substituents are indicated by Yb in general Formula I, wherein Y maybe defined as selected from the group consisting of hydrogen, hydroxyl,metal-oxy, ester, keto, alkoxy, alkyl sulfide, aryl sulfide, aroxy,ether alcohol, aldehyde, thioaldehyde, oxime, amido, thioamido,carbamido, aralkyl, aryl, alkaryl, halogen, nitroso, amino, nitrosamino,amidino, imino, N-thio, diazo, hydrazino, cyano, azoxy, azo, and hydrazoradicals, and b represents the number of Y's and is equal to zero or awhole number corresponding to the number of available hydrogens on thenucleus T not substituted with R, Z.COOM, and Zn.

In general it appears that any metal may be employed as the metal M incompounds or condensation products of the aforesaid type to providevaluableoil addition agents. The metals contemplated herein may bebroadly classified as metals of groups I to VIII inclusive of theperiodic system. These metals comprise the following: the alkali metals:lithium, sodium, potassium, rubidium, and caesium; the alkaline earthgroup: beryllium, magnesium, calcium, strontium, and barium; the metalszinc, cadmium, mercury, scandium; the metals aluminum, gallium, indium,thallium, titanium, zirconium, cerium, thorium, germanium, tin, andlead; vanadium, columbium. and tantalum; arsenic, antimony, and bismuth;chromium,'molybdenum, tungsten, and uranium; rhenium, manganese. iron,cobalt, and nickel; ruthenium, rhodium, and palladium; .osmium, iridium,and platinum.

Some of the rare earth metals are given in the foregoing. Other rareearth metals suitable for use in the aliphatic carboxylate" group(Z.COOM) of these condensation products are those now commerciallyavailable as the cerium and yttrium group, namely, a mixture ofpraseodymium, neodymium, samarium, europlum, gadolinium, terbium,dypsprosium, holmium, erbium, thallium and lutecium.

The selection of a metal will, of course, depend to a certain extentupon the character of the oil in which the addition agent is to be addedand the conditions under which it is to be used. Certain metals such aslead, zinc, and tin, for example, may contribute to the oilinesscharacteristics of the oil. For use in addition agents for internalcombustion engine lubricants, my present work indicates tin as being aspecially preferred metal.

As aforesaid, the aryl nucleus T may be mono or polycyclic,corresponding, for example, to benzene, naphthalene, and anthracene andtheir derivatives. A typical condensation product in which the arylnucleus is monocyclic and is otherwise unsubstituted may in its simplestform be represented by the general formula:

OH R R 011 Another typical desirable condensation prodnot having a Ysubstituent is one in which Y is an ether group (aroxy or alkoxy) whichmay, in its simplest form be represented by the formula:

Moooz zrooru R RAXQR in which R represents an alkyl or an aryl group.Since the condensation reaction employed in synthesizing the sulfides(or corresponding selenides and tellurides) may be attended by furthercondensation, such further condensed products (hereinafter termedpolymers") are contemplated herein as coming within the general FormulaI above and the terms sulfides," condensation products etc. are usedherein to identify and define-these oil addition agents. Polymers ofthis character which may be associated with or formed instead of thesimple condensation product of Formula 11 may be represented by thefollowing formula:

Z.COOM Z.COOM Z.COOM

of a "wax-phenol" in which two or more phenol groups are interconnectedby one or more aliphatic hydrocarbon chains. Com-pounds of this typewhen converted to the wax substituted phen01 aliphatic acids and furtherreacted to form the metal carboxylates of phenol aliphatic acid sulfidesmay result in the formation of condensation products corresponding tothe formula:

in which the chains represent the oil solu'bilizing alkyl substituents Rof general Formula I.

The foregoing discussion pertaining to Formulae H to VII inclusive isnot intended as a development of the specific molecular compositions orstructure of condensation products constituting the mineral oil additionagents contemplated herein, but is merely intended as indicative of thepossible composition of such addition agents. These addition agents maybe broadly. characterized as the sulfides or the corresponding selenidesor tellurides) of alkylated aromatic-aliphatic acid salts or thesulfides of alkylated aromatic-aliphatic carboxylic acids in which thecarboxyl hydrogen is substituted with its equivalent weight of metal.The sulfur condensation products may also be characterized as metalcarboxylates of alkylated aromatic-aliphatic acid sulfides.

As aforesaid the term sulfide" as used herein is inclusive of themonosulfides, disulfides. trisulfldes. tetrasulfides, etc; that is itincludes both monosulfides and polysulfides and it is also intended toinclude such polymers and related derivatives as may be formed by thehereinafter described typical procedures which may be emplayed tosynthesize the condensation products contemplated herein. It i alsopointed out that the so-called polymer products typified by Formulae VIand VII are included under general Formula I since these polymers arecharacterized by having therein at least one grouping typifled bygeneral Formula I.

The sulfides or sulfur derivatives of alkylated aromatic-aliphaticacidsalts are the preferred sulfur dichloride (S012) is used in thisgeneral procedure, the condensation product will be in the nature of amonosulfide (or polymer thereof) sulfur monochloride (SzClz) will yieldthe corresponding disulfide (or polymer thereof) and a mixture of sulfurmonochloride and sulfur di=- chloride may be employed to obtain acorresponding mixture of condensation products. Elementary sulfur may beemployed as the condensation reagent, but this is not considered themostdesirable procedure.

Sulfur derivatives of higher sulfur content may be obtained by reactinga condensation product having the disulfide linkage with sulfur or withalkali polysulfide or with an alkyl tetrasulfide. Such higher sulfurderivatives may also be obtained by first reducing the disulfide to forma thiophenol of the alkylated aromatic-aliphatic acid and then reactingthe thiophenol with su1- fur dichloride (to form the trisulfide) or withsulful monochloride (to form the tetrasulfide).

The alkylated aromatic-aliphatic acids used in preparing the sulfur,selenium or tellurium con densation products from which thecorresponding metal carboxylates are formed, may be obtained in variousways. Details in desirable procedures for obtaining the preferredwax-substituted aromatic-aliphatic acids are described in the aforesaidcopending application 300,010 Where such acids are intermediate productsin the formation of the wax substituted aromatic-aliphatic acid saltsdescribed and claimed in that application.

The first step in synthesizing the sulfide of alkylatedaromatic-aliphatic acid salts, is to prepare the alkylated aromaticcompound. This, for the preferred multifunctional compounds, involvesfirst condensing a high molecular weight aliphatic hydrocarbon materialwith the desired aromatic compound, which, as aforesaid, may carry othersubstituents such as a hydroxyl group, an aroxy group or the like. Inthis condensation reaction pure or substantially pure high molecularweight aliphatic compounds may be employed, or the aliphatic materialmay be a mixture predominantly comprised of aliphatic compound having atleast twenty carbon atoms, such a mixture being typified by a petroleumwax such as paraffin wax. The condensation may be effected by firsthalogenating the aliphatic material and condensing same with aromaticmaterial by means of a Friedel-Crafts catalytic reaction (described indetail in application 300,010). The alkylation may also be carried outwith high 5.3T molecular weight unsaturated aliphatic hydroclass ofcondensation products contemplated herein, and for that reason theinvention will be specifically described in connection with the sulfurderivatives, although, as aforesaid, the corresponding selenides andtellurides are contemplated as coming within the scope of the inven-'tion.

One general procedure for synthesizing the carbons or with highmolecular weight alcohols, using sulfuric acid or aluminum chloride as acatalyst. Also the high molecular weight alcohol may be converted to analkyl halide and condensed with the aromatic material by means of theFriedel-Crafts reaction.

Since paraffin wax or broadly petroleum wax is considered to be apreferred source for the heavy alkyl substituent, such preferred alkylsubstituted aromatic compounds for obtaining alkylated aryl aliphaticacid salts of multifunctional properties may be referred to herein aswax-aryl compounds. By this term it is to be understood that I intend toinclude equivalent alkylated aromatics in which the alkyl substituent isderived from pure or mixed aliphatic compounds or materials equivalentin character to those in petroleum wax and it is also to be understoodthat there are included wax aryl compounds in which the aryl nucleuscontains another or other substituents such as an hydroxyl group, anether group or the like.

In obtaining the wax aryl compounds I may employ, for example, achlorinated petroleum wax having from percent to 16 percent chlorinecontent. The degree of alkylation of the product may be varied byvarying the chlorine content or the aliphatic material (wax) and theratio of chlorinated wax and aromatic compound in the reaction mixture.A convenient means'of indicating this degree of alkylation is by meansof a parenthetical expression (AB) in which A indicates the atomicproportions of chlorine per mol of aromatic compound in the mixture andB indicates the percentage chlorine content of the chlorinated material.Thus "wax-phenol 3-16)" indicates that 3 atomic proportions of chlorinea chlorinated wax of 16 percent chlorine content) were present for eachmol of phenol in the reaction mixture. This same expression will be usedin connection with derivatives of the alkylated aromatic compound, as,for example, the metal carboxylates of wax-phenolstearic acid sulfide(3-16).

After obtaining the wax-aromatic condensation product, such product iscondensed with an aliphatic or cyclo-aliphatic carboxylic acid to obtainthe wax substituted aromatic-alkyl carboxylic acid. Specific procedureswhich may be followed in efl'ecting the condensation between thewax-aromatic compound and the aliphatic acid are as follows:

a) Condensation of alkylated aromatic or hydroxyaromatic compounds withunsaturated aliphatic acids such as oleic acid, using a so-calledkationoid catalyst such as sulfuric acid, zinc chloride. aluminumchloride, etc., to effect the addition of the unsaturated acid to thearyl nucleus.

1)) Condensation of an alkylated aromatic or hydroxyaromatic hydrocarbonwith halogenated aliphatic or cyclo-aliphatic acids, such aschloracetic, chlorstearic and chlornaphthenlc acids, by means of theFriedel-Crafts reaction using anhydrous aluminum chloride as thepreferred catalyst.

c) In the case of acids of the type contemplated herein which contain ahydroxyl substituent in the aromatic nucleus, such acids may be preparedby a rearrangement of the corresponding alkylated aryl ether aliphaticacids in the presence of a kationoid catalyst such as H01 gas.

di Hydroxyl-aliphatic acids can be converted to the corresponding etheraryl-aliphatic acids by methylating the hydroxyl group by reaction withalkylating agents like dimethyl sulphate or alkyl halides or by reactionwith arylating agents such' as aryl halides.

When it is desired to obtain a compound or condensation product in whichthe characterizing aryl nucleus contains, in addition to or instead ofresidual hydrogen and the heavy alkyl group or groups and alkyl-carboxylgroup, a substituent of the type classified in general Formula I as Yb,it is pointed out that. with the exception of substituents such ashydroxyl, aroxy, aralkyl, aryl. alkaryl. and halogen, such Y groups arein troduced after alkylation and introduction of the alkyl-carboxylgroup. The usual methods for introduction of these last mentioned Ysubstitucnts into non-alkylated aromatic compounds may be employed inconnection with the alkylated aromatic-alkyl acids and it is to beunderstood that the introduction of these substituents into the aromaticnucleus will in some cases be accompanied by similar substitution in theheavy alkyl substituent and in the aliphatic acid group.

Examples of the aromatic compounds which may be used as startingmaterials for the alkylation or wax-condensation reaction for obtainingeither a product in which the aromatic nucleus is otherwiseunsubstituted or a product in which the aromatic nucleus carries ahydroxyl group are as follows: benzene, naphthalene and anthracene(either substituted or unsubstituted) phenol, resorcinol, hydroquinone,catechol, cresol, hydroxyl-diphenyl, benzlyphenol, alphaand betanaphtholand beta-methylnaphthol, anthranol, phenylmethylnaphthol, etc.; and arylethers such as diphenyl ether and naphthyl ether, or mixed alkyl-aryl oraralkyl-aryl ethers such as anisole, naphthylmethyl ether andbenzylphenyl ether. Preference in general, as has been previouslyindicated, is to the monoand poly-cyclic aromatics preferablynaphthalene) and to the mono-hydroxyphenols otherwise unsubstituted,particular preference being given to phenol and alphaand beta-naphthol.

As sources for the heavy alkyl multifunctional imparting substituent weprefer to use, as has been previously indicated, a mixture of highmolecular weight aliphatic hydrocarbons such as characterize petroleumwax, particular preference being given to paraffin wax.

Other sources of the heavy alkyl substituent are high molecular weightunsaturated aliphatic hydrocarbons such as polymerized iso-butylene,dodecylene, tetra-decylene, octa-decylene, melene, etc., and highmolecular weight alcohols, such as myricyl alcohol, ceryl alcohol, etc.Although the above mentioned aromatic compounds can be alkylated bydirect reaction with high molecular weight alcohols, the preferredprocedure consists in conversion of the alcohol to the correspondinghalide (or polyhalide), followed by condensation of the alkyl halidewith the aromatic compound by the Friedel-Crafts reaction.

As has been previously indicated, the allevl carboxylate substituent maybe derived from any aliphatic or cyclo-aliphatic monoor poly-basiccarboxylic acid, illustrative sources of which are acetic, benzoic,butyric, valeric. heptylic, nonylic, palmitic and stearic acids, whichtypify saturated acids, and must be used as the corresponding chlor-acidin which substitution takes place at the alpha carbon atoms of thealiphatic acid group. Other aliphatic acid substituents may be obtainedby using unsaturated carboxylic acids of the oleic series, CnHZn-202, inwhich case substitution on the nucleus takes place at the double bond inthe unsaturated acid. Halogenated cyclo-aliphatic acids such aschlor-naphthenic acid may be used to obtain compounds in which thealkylated aromatic group carries a cyclo-ali phatic substituent. Theterm alkyl or aliphatic" when used herein in connection with thealiphatic carboxylate substituent is intended as inclusive of bothaliphatic and cyclo-aliphatic acid groups or radicals.

As aforesaid the preferred procedure for obtaining the sulfides from thealkyated aromaticallphatic acids involves reacting the acid with asulfur halide. This may be accomplished by dissolving the alkylatedaromatic-aliphatic acid or mineral oil solution thereof in a suitablesolvent such as carbon disulfide, benzene, chlorbenzene, ethylenedichloride, Stoddard Solvent or the like. The temperature of thesolution may be brought up to about F., and a sulfur chloride or amixture of sulfur chlorides is added in the ratio of about mol per molof the acid.

The addition of the sulfur halide should be sufficiently slow to preventthe temperature substantially exceeding 100 F. and the mixture may beheld at that temperature for about one hour to complete formation of thesulfur derivative. Hydrogen chloride is evolved in the reactionresulting in fixation of the sulfur in the aryl nucleus.

As regards the temperature of the reaction it is to be understood thatthe reaction can be carried out at various temperatures from roomtemperature up to the boiling point of the solvent, but it is preferablefor obtaining light colored products that the temperature be not toohigh.

After completion of the sulfur condensation the reaction mixture iswater washed to remove dissolved hydrochloric acid and the freealkylated aromatic alkyl carboxylic acid is converted to itscorresponding alkali metal salt or carboxylate by reaction with analkali alcoholate. Salts of other metals are obtained by doubledecomposition of the alkali salt with a normal inorganic or fatty acidsalt or oxy salt of the desired metal carrying out the reaction inaqueous or non aqueous medium. When the reaction is carried out inaqueous medium, it is suitable to form the alkali salt by reaction withan aqueous solution of sodium hydroxide in place of an alkalialcoholate. If it is desired to btain a condensation product in whichthe aryl nucleus carries a metal oxy substituent (a metal phenate-metalcarboxylate salt of an alkylated phenol aliphatic acid sulfide) themetallizing reaction is carried out in a nonaqueous medium. Anotherdesirable procedure for formation of the salts of polyvalent metals,

consists in reacting the free alkylated aromatic alkyl acid with analcoholate of the desired metal. This reaction is carried out mostreadily by adding the inorganic salt in alcohol solution to the freeacid, followed by addition of an equivalent amount of alkali alcoholate,whereby the alcoholate of the polyvalent metal is formed in the reactionmixture.

Further details in typical procedures which may be followed insynthesizing themetal carboxylates of alkylated aromatic-aliphatic acidsulfides contemplated herein as oil improving agents will appear fromthe following examples: v

EXAMPLE ONE STANNOUS CAaBoxYLArn or WAX-PHENOL STEARIC Acro DrsorrrnaReactionmirture Parts by weight Wax-phenol stearic acid (3-14) 100Mineral oil of 67 sec. Saybolt vis. at 210 F.

as diluent 300 Sulfur monochloride 5.05 Sodium (dissolved in butanol assodium butylate) 3.46 stannous chloride (anhydrous) 7.1

Reaction procedure Wax phenol stearic acid is prepared by thecondensation of wax phenol (3-14) with oleic acid according to theprocedure described in Examples Mal-(b) of the aforesaid Patent2,198,275, followed by diluting with mineral oil and converting to thesodium phenate-sodium carboxylate salt by reaction with sodium butylateby heating a mixture thereof at the reflux temperature (about 225 F.)for one hour. The sodium salt is then further diluted with butanol untilthe mixture can be stirred readily at 100 F., followed by addition ofthe ScClz at this temperature at a rate sufficiently slow to avoidappreciable temperature rise by the heat of reaction developed. Themixture is then stirred at this tem-- perature about one hour tocomplete the sulfurization. In the reaction with sulfur monochloride,one-half of the sodium is neutralized by reaction with hydrochloricacid, leaving the sodium carboxylate of the wax phenol stearic aciddisulfide as the reaction product. The stannous salt is then formed byadding the stannous chloride in solution in butanol, and heating at thereflux temperature about one hour, whereby .double decomposition takesplace between the stannous chloride and the sodium salt to form thestannous carboxylate of wax phenol stearic acid disulfide. The alcoholis then distilled and the reaction product is filtered through Hi-Flo toremove sodium chloride. The product is then steam treated at about 300F. until all traces of alcohol solvent are removed. Upon cooling, vacuumis applied or a current of nitrogen is run through the mixture to removewater Vapor to obtain the finished product, which is approximately a Ablend in mineral oil.

EXAMPLE TWO Srsrmous PHENATE-STANNOUS CARBOXYLATE or Wax PHENOL STEARICAcro DISULFIDE Reaction mixture Parts by weight Wax-phenol stearic acid(3-14) 100 Mineral oil of 67 sec. Say. vis. at 210 F.

as diluent 300 Sodium (dissolved in butanol as sodium butylate) 5.19Sulfur monochloride 5.05 Stannous chloride (anhydrous) 14.2

Reaction procedure The sodium salt of the wax-phenol stearic aciddisulfide is formed by the procedure of Example One. In order tosubstitute both the phenolic -(OH) group and the carboxyl group withtin,

EXAMPLE THREE STANNOUS CARBOXYLATE 0F WAX-PHENOXY PHENYL STEARIC AcmDISULFIDE Reaction mixture Parts by weight Wax-phenoxy phenyl stearicacid (Ii-16)-- Mineral oil of 67 sec. Say. vis. at 210 F.

or diluent 200 Sulfur monochloride 6.0 Sodium (dissolved in butanol orsodium butylate) 2.0 stannous chloride (anhydrous) 8.5

Reaction procedure Wax-phenoxy phenyl stearic acid is prepared by thecondensation of wax-phenyl ether (3-16) with oleic acid according to thprocedure described in Example 3(a) of Patent 2,198,275, followed bydiluting with mineral oil and converting to the sodium salt by reactionwith sodium butylate by heating a mixture thereof at the reiiuxtemperature of the butanol for one hour. The sulfur monochloride is thenadded at about 100 F. at a rate regulated to prevent appreciabletemperature rise by the heat of reaction developed. The mixture is thenstirred at this temperature one hour to complete the sulfurization. Inthe reaction with the sulfur monochloride, the sodium salt isneutralized by reaction with the hydrochloric acid formed, resulting information of the wax-phenoxy phenyl stearic acid disulfide as reactionproduct. In order to form the stannous salt, the stannous chloride isadded to the free acid, followed by addition of an equivalent amount ofsodium butylaie and heating at the reflux temperature about one hour tocomplete the reaction. In this reaction. stannous butylate is formed byreaction of the stannous chloride with the sodium butylate, which inturn is reacted with the carboxyl group to form the stannous carboxylatederivative. The

alcohol is then distilled and the reaction product is filtered to removesodium chloride. The prodnot is then steam-treated at about 300 F. toremove any traces of solvent. Upon cooling, vacuum is applied or acurrent of nitrogen is run through the mixture to remove water vapor toive the finished product.

To demonstrate the improved properties obtained in mineral oil blendscontaining addition agents of the type discussed herein, I haveconducted several comparative tests with representative mineral oilsalone and with the same oils blended with representative metalcarboxylates of alkylated aromatic-aliphatic carboxylic acid sulfides.The results or such tests are discussed in the following examples:

EXAMPLE A Pour point depression These tests were conducted with a motoroil having a Saybolt viscosity of 67 seconds at 210 F. and a pour pointof F. The pour point of blends formed from this oil and representativeaddition agents of the type contemplated herein are listed in Table Ibelow, from which it will be observed that these addition agents areeflective pour point depressants when the alkyl substituent is derivedfrom a high molecular weight aliphatic material such a petroleum wax.

Viscosity index improvement The data listed in Table II below showingthe eflectiveness of typical addition agents contemplated herein forimproving viscosity index (V. I.) were obtained in the conventionalmanner from the Saybolt viscosity (Say. vis.) of the oil and the oilblends at 100 F. and 210 F. The oil used was a viscous mineral oil ofthe lubricant type.

. conditions.

TABLE II Say. vis. Conc.

Addition agent by WL Per cent None Stannous carboxylate of wax-phenolsteric acid (iisulflde (3-14) 1 Stannous phenate-stannous carboxylate ofwax-phenol stearic-acid riisulfldo (3-14) l Stannous carboxylate ofwaxhenoxy phony] swag-Dc acid disulfldc l obaitous carhox yiate oiwax-phenoxy phenyl stcui'ic acid disulfidc (3-16) EXAMPLE COxidation-inhibition In addition to the foregoing tests I have also madecomparative tests between an oil and an oil blend containingrepresentative improving agents of the type contemplated herein todetermine the comparative behavior of the unblended oil and the improvedoil under actual operating The tests were carried out in a singlecylinder Lauson engine operated continuously over a time interval of 16hours with the cooling medium held at a temperature of about 212 F. andthe oil temperature held at about 280 F. The engine was operated at aspeed of about 1830 R. P. M.

The oil used in the test was a lubricating oil stock of 45 sec. Sayboltviscosity at 210 F. and the conditions observed were:

a. The amount of naphtha insoluble material formed in the oil.

I). The neutralization number or acidity (N. N.) of the oil.

0. The .S. U. V. of the oil before and after the test.

In running these tests, comparative runs were made with a sample of theblank oil for each sample of oil containing the addition agent. In TableIII below, these blank 011 samples are indicated by A1, A2, etc.; andoils with addition agents used in corresponding runs are indicated byB1, B2. etc. The oil blends contained addition agents as follows:

Bi= stannous phenate-stannous carboxylate of wax-hydroxyphenyl stearicacid disulfide B2= chromous phenate-chromous carboxylate ofwax-hydroxyphenyl stearic acid disulfide (3-14) Ba= stannous carboxylateof wax-phenoxyphenyl stearic acid disulflde (3-16) B4= stannouscarboxylate of wax-naphthyl stearic acid disulfide (3-46) TABLE III Percent on g- N. N. naphtha insolubles .ss. 2 10.0 0. 11 45. a o. s o. 2203. a 12.9 n. so as. s z. a 0. 21 52. 5 x. 4 0. 18 4c. 1 o. 2 o. 20 (i9.1 s. l 0. 15 -18. a z. 1 o. 29

The amountof improving agent used in the oil may be varied, dependingupon the character of the oil with which it is blended and theproperties desired in the final oil composition. The sulfides ofalkylated aromatic-aliphatic acid salts contemplated herein may be usedin amounts ranging from about V; per cent to about per cent, and ingeneral mineral oil compositions of the desired improved properties maybe obtained with amounts in the neighborhood of 1 per cent by weight.

It is to be understood that while I have described certain preferredprocedures which may be followed in the preparation of these sulfides ofalkylated aromatic-aliphatic acid salts and have referred to variousrepresentative constituents thereof, such procedures and constituentsare for illustrative purposes only. The invention, therefore, is not tobe construed as limited by the specific examples given but includeswithin its scope such changes and modifications as fairly come withinthe spirit of the appended claims.

I claim:

1. An improved mineral oil composition comprising a mineral oil havingadmixed therewith in minor proportion an oil-miscible condensationproduct characterized by at least two aromatic nuclei, each of which issubstituted with at least one oil-solubiiizing alkyl group and with atleast one aliphatic carboxylic acid group wherein the carboxyl hydrogenis substituted with metal, the said characterizing nuclei 'beinginterconnected by at least one atom of an element selected from thegroup consisting of sulfur, selenium. and tellurium.

2. An improved mineral oil composition comprising a mineral oil havingadmixed therewith in minor proportion an oil-miscible condensationproduct characterized by at least two aromaticnuclei, each of which hasat least one nuclear hydrogen atom substituted with an hydroxyl groupand each characterizing nucleus being further substituted with at leastone oil-solubilizing alkyl group and with at least one aliphaticcarboxylic acid group wherein the carboxyl hydrogen is substituted withmetal, the said characterizing nuclei being interconnected by at leastone atom of an element selected from the group consisting of sulfur,selenium, and tellurium.

3. An improved mineral oil composition comprising a mineral oil havingadmixed therewith in minor proportion an oil-miscible condensationproduct characterized by at least two aromatic nuclei, each of which issubstituted with at least one oil-solubilizing alkyl group having atleast twenty carbon atoms and with at least one aliphatic carboxylicacid group wherein the carboxyl hydrogen is substituted with metal, thesaid characterizing nuclei being interconnected by at least one atom ofan element selected from the group consisting of sulfur, selenium, andtellurium.

4. An improved mineral oil composition comprising a mineral oil havingadmixed therewith in minor proportion an oil-miscible condensationproduct characterized by at least two aromatic nuclei, each of which hasat least one nuclear hydrogen atom substituted with an hydroxyl groupand each characterizing nucleus being further substituted with at leastone oil-solubilizing alkyl group having at least twenty carbon atoms andwith at least one aliphatic carboxylic acid group wherein the carboxylhydrogen is substituted with metal, the said characterizing nuclei beinginterconnected by at least one atom of an element selected from thegroup consisting of sulfur, selenium, and tellurium.

5. An improved mineral oil composition com prising a mineral oil havingadmixed therewith a minor proportion of an oil-miscible sulfide of awax-substituted aromatic-aliphatic carboxylic acid salt in which thecarboxyl hydrogen is substituted with its equivalent weight of metal.

6. An improved mineral oil composition comprising a mineral oil havingadmixed therewith a minor proportion of an oil-miscible monosulfide of awax-substituted aromatic-aliphatic carboxylic acid salt in which thecarboxyl hydrogen is substituted with its equivalent weight of metal.

7. An improved mineral oil composition comprising a mineral oil havingadmixed therewith a minor proportion of an oil-miscible polysulfide of awax-substituted aromatic-aliphatic carboxylic acid salt in which thecarboxyl hydrogen is substituted with its equivalent weight of metal.

8. An improved mineral oil composition comprising a mineral oil havingadmixed therewith a minor proportion of an oil-miscible sulfide of awax-substituted aromatic-aliphatic carboxylic acid salt in which thecarboxyl hydrogen is substituted with its equivalent weight of metal andin which at least one nuclear hydrogen atom of the characterizingwax-substituted aromatic nucleus is substituted with an hydroxyl group.

9. An improved mineral oil composition comprising a mineral oil havingadmixed therewith a minor proportion of an oil-miscible sulfide of awax-substituted aromatic-aliphatic carboxylic acid salt in which thecarboxyl hydrogen is substituted with its equivalent weight of metal andin which at least one nuclear hydrogen atom of the characterizingwax-substituted aromatic nucleus is substituted with a metal-oxy group.

10, An improved mineral oil composition comprising a mineral oil havingadmixed therewith a minor proportion of an oil miscible sulfide of awax-substituted aromatic -aliphatic carboxylic acid salt in which thecarboxyl hydrogen is substituted with its equivalent weight of metal andin which at least one nuclear hydrogen atom of the characterizingwax-substituted aromatic nucleus is substituted with an aroxy group.

11. An improved mineral oil composition comprising a mineral oil havingadmixed therewith a minor proportion of an oil-miscible sulfide of thestannous carboxyiate of a wax-substituted aromatic-aliphatic acid.

12. An improved mineral oil composition comprising a mineral oil havingadmixed therewith a minor proportion, from percent to 10 percent, of anoil-miscible sulfide of an alkyl-substituted aromatic carboxylic acidsalt in which the carboxyl hydrogen is substituted with its equivalentweight of metal.

I 13. An improved mineral oil composition comprising a mineral oilhaving admixed therewith a minor proportion, from A; percent to 10percent, of an oil-miscible sulfide of an alkyl-substituted aromaticcarboxylic acid salt in which the carboxyl hydrogen is substituted withits equivalent weight of metal and in which said alkyl substituent isderived from an aliphatic hydrocarbon having at least twenty carbonatoms.

14. An improved mineral oil composition comprising a mineral oil havingadmixed therewith a minor proportion of a metal organic condensationproduct characterized by having at least once therein the groupingcorresponding to the general formula in which T represents an aromaticnucleus; Z represents a hydrocarbon radical selected from the groupconsisting of aliphatic and cycloaliphatic hydrocarbon radicals attachedto the nucleus T; COOM represents at least one carboxyl group attachedto the radical Z, the carboxyl hydrogen thereof being replaced by ametal M; R represents at least one oil solubilizing alkyl group; Y isselected from the group consisting of hydrogen, hydroxyl, metal-oxy,ester, keto, alkoxy, alkyl sulfide, aryl sulfide, aronv, ether alcohol,aldehyde, thioaldehyde, oxime, amido, thioamido, carbamido, aralkyl,aryl, alkaryl, halogen, nitroso, amino, nitrosamino, amidino, imino,N-thio, diazo, hydrazino, cyano, azoxy, azo, and hydrazo radicals; brepresents the number of Y substituents and is equal to zero or a wholenumber corresponding to available hydrogens on the nucleus T notsubstituted with R, Z.COOM and Sn; .3 represents an element selectedfrom the group consisting of sulfur, selenium and tellurium; and nrepresents a whole number from one to four.

15. An improved mineral oil composition comprising a mineral oil havingadmixed therewith a minor proportion of a metal organic condensationproduct characterized by having at least once therein the groupingcorresponding to the genin which '1 represents an aromatic nucleus; Z

represents a hydrocarbon radical selected from the group consisting ofaliphatic and cycloaliphatic hydrocarbon radicals attached to thenucleus T; COOM represents at least one car boxyl group attached to theradical Z, the carboxyl hydrogen thereof being replaced by a metal M; Rrepresents at least one alkyl group having at least twenty carbon atoms;Y represents a radical selected from the group consisting of hydrogen,hydroxyl, metal-oxy, ester, keto, alkoxy, alkyl sulfide, aryl sulfide,aroxy, ether alcohol, aldehyde, thioaldehyde, oxirne, amido, thioamido,carbamido, aralkyl, aryl, alkaryl, halogen, nitroso, amino, nitrosamino,amidino, imino, N-thio, diazo, hydrazino, cyano, azoxy, azo and hydrazoradicals; b represents the number of Y substituents and is equal to zeroor a whole number corresponding to available hydrogens on the nucleus Tnot substituted with R, Z.COOM'and 2n; 2 represents an element selectedfrom the group consisting of sulfur, selenium and tellurium; and nrepresents a whole number from one to four.

16. An improved mineral oil composition comprising a mineral oil havingadmixed therewith a minor proportion of the disulfide of the stannousphenate-stannous carboxylate of wax-phenol stearic acid.

ORLAND M. REIFF.

